Get a F-15 Agressor one
Get all planes that you can recieve from missions and tactical challenges, and they reward you with the F-15 Agressor one

Recieve F-15 Aggressor two
In free flight mode choose mission 21 and assign two enemies to battle you. Defeat them with the F-15 aggressor one and you got yourself the F-15 aggressor two

Bonus stages
Complete all fighter missions and tactical challenges to get free flight in missions 20 and 21.

Recieve a T-3 super recipro
Score over 100 kills and you get the T-3 super recipro fighter.

F-18 aggressor
You must have 10 or more carrier landings in one of the two carrier free flight missions. Don't forget to choose a carrier base aircraft and no enemy's.

Unlock all planes and missions
To unlock all planes and missions hold L and hit X and Y simultaneously. An audio confirmation will occur, may have to be entered multiple times.